Preheat the oven to 350F (177C) convection (325F/163C conventional) and lightly grease and line the bottom of two 8 inch (20 cm) round pans with baking spray and parchment paper.
In a large bowl or the bowl of a stand mixer, use a whisk attachment to beat together the egg whites and the granulated sugar. Beat for a few minutes at full speed, just until the meringue is fluffy and holds stiff peaks.
4 large eggs, 1 1/2 cup (300g) granulated sugar
Add the egg yolks and vanilla extract and beat at medium speed, just until they’re combined, a few seconds.
4 large eggs, 1 tsp vanilla extract
Sift the flour, baking powder and salt over the batter and turn the mixer up to medium speed, just until it’s combined.
1 1/2 cups (180g) all-purpose flour, 2 tsp baking powder, 1/4 tsp fine sea salt
In another bowl, use an electric mixer with the whisk attachment to whip the cream just until it holds stiff peaks.
1 cup (9oz) heavy whipping cream
Fold the whipped cream into the batter just until it's fully combined and smooth.
Use a rubber spatula to scrape the edge of the bowl and distribute the batter evenly between the prepared pans, about 15-16 ounces each. Bake for about 25 minutes. The tops should be golden brown and spring back when you gently press on the center.
Remove the cakes from the oven and run a knife around the edge of the cake to release it from the pan. Allow it to cool for 15 minutes in the pan and then remove the cakes and place them onto a cooling rack or a tea towel.
Allow the cake to cool completely and if desired, use a large serrated knife to slice each layer in half or use as desired.